Projectiles known in the prior art have various disadvantages. For the most part, they are lead-based, causing them to generate considerable pollution in firing ranges during training and competitions. Additionally, when used outdoors, their kinetic energy dissipates very slowly. For this reason, when used in public, they are capable of passing through two people, one after the other, making them especially dangerous. Because of this they are incompatible with use by police forces.
Publication FR-A-2 517 764 describes a training shell used for shooting training and regulating artillery pieces. This training shell is specifically designed for short distance simulations of actual longer range firings in order to identify the reasons for lack of precision and to better regulate the weapon. To recreate realistic control conditions, the precision of the short range firing of the shell is altered. In order for this to occur, the shell comprises an interior cavity, with one extremity having a flat area and a hollow portion designed to modify the shell's center of gravity. The hollow portion is asymmetrical so that once the shell is caused to rotate by the grooves in the gun barrel, its trajectory deviates slightly. This shell does not ensure a precise trajectory and cannot be adapted to handguns. Therefore it does not offer a satisfactory solution.
Publication EP-A-0 015 574 describes a hunting projectile comprising helicoidal grooves that resist rotation during the projectile's trajectory. Thus, once the projectile has traveled for a certain distance, for example 300 meters for hunting weapon projectiles, the helicoidal grooves slow rotation on the trajectory, making it unstable and causing it to tilt down toward the ground. Therefore, the course of the projectile is stopped prematurely. Its maximum range is shortened. The helicoidal grooves that provide a cleaner impact orifice have no immediate slowing effect. Therefore, this solution is not satisfactory.
Publication U.S. Pat. No. 6,363,856 describes ammunition for a handgun with an extremity that comprises a flat area. Because the projectile has a smaller mass than projectiles in current use, when it is discharged the speed of the projectile decreases rapidly, reducing the range of danger. This ammunition further comprises a jacket which separates from the projectile on impact, giving it additional power to simultaneously penetrate the target and fragment so the projectile does not reach unintended targets. This projectile is lightened through the use of very light resins that considerably diminish its aerodynamics and the precision of its trajectory. Therefore, this is not a satisfactory solution.
Publication FR-A-2 820 495 describes an ammunition projectile of reduced range comprising a hollow body extending into a rounded nose cone having a plurality of hollow impressions defined by two planes forming a dihedron with its central ridge parallel to the axis of the nose cone. These hollow impressions are designed to slow the rotation of the projectile imposed by the ridges in the gun barrel. Thus, as with publication EP-A-0 015 574, the projectiles are slowed by destabilizing them. Because these projectiles leave their trajectory in mid course, their range is reduced. Slowing does not occur immediately. Thus, this solution is unsatisfactory.